If you only have Access Runtime you can't.
You need the full Retail version of Access to add or set those design
elements.
Think of Runtime sort of as "Access Viewer". But unlike the free Viewers
Microsoft makes available for Excel and Word, someone with the retail
version has to properly set up an Access file to be "viewed" in Runtime. So
you may be out of luck. (and to avoid any possible confusion, Access Runtime
files are NOT free. Developers pay for the right to distribute them with
their applications, so, speaking as a developer, I can assure you they are
NOT free.)
And we are talking a *fairly advanced* someone (i.e., developer level), who
probably already knows the answers to the questions you just casually asked.
Sorry if that seems overly blunt, it really isn't meant that way. It's just
that those are only the first of many, many questions you'll be asking if
you pursue this.
But, assuming you have a Retail version available to you and want to proceed
(and ignoring the "how did you get the Runtime files?" issue):
1) Under Tools>Startup you can specify a startup form under "Display
Form/Page"
2) AFAIK, the only way to create a CustomMenuBar (not a CustomToolbar) is
with code. Then you can fill in the Tools>Startup>MenuBar property, either
in that dialog or by macro or by code.
Hope this helps,